Mechanisms of mRNA localization and translational control in Drosophila development

果蝇发育中 mRNA 定位和翻译控制的机制

• 批准号: 10377348
• 负责人: ELIZABETH R GAVIS
• 金额: $ 62.04万
• 依托单位: PRINCETON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-04-01 至 2023-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10377348
• 关键词: Animals; Behavior; Biochemical; Cells; Code; Complex; Coupling; Cytoplasmic Granules; Dependence; Destinations; Development; Diffusion; Drosophila genus; Embryonic Development; Ensure; Event; Fertility; Genes; Genetic Transcription; Genome; Genomic approach; Germ; Germ Cells; Goals; Impairment; Infertility; Label; Location; Mediating; Messenger RNA; Methods; Microscopy; Modeling; Monitor; Movement; Neoplasm Metastasis; Neurodegenerative Disorders; Nurses; Oocytes; Ovarian; Pattern; Play; Process; Production; Property; Protein Biosynthesis; Proteins; RNA; Rana; Regulatory Element; Research; Ribonucleoproteins; Ribosomes; Role; Site; Specificity; Structure; Structure of primordial sex cell; Transcript; Translating; Translational Activation; Translations; cohort; egg; fly; high resolution imaging; in vivo; in vivo imaging; innovation; nano; programs; protein distribution; protein expression

PROJECT SUMMARY Our long-term research goal is to understand post-transcriptional mechanisms that control gene activity during early animal development. We focus on intracellular mRNA localization and translational control, which play crucial roles in regulating the production of proteins from maternally supplied transcripts. Because these transcripts, which control the initial developmental program of nearly all animals, are pre-loaded in the egg, the spatial and temporal expression of the proteins they encode must be exerted post-transcriptionally. In animals as diverse as flies and frogs, mRNA localization and local control of translation produce asymmetric protein distributions required for axis formation, patterning, and germline development. Often many different transcripts must be localized concurrently to various subcellular locations. Additionally, translational control must be superimposed to repress unlocalized transcripts and activate properly localized transcripts. How specificity is conferred on these processes, so that each transcript is targeted to its correct destination and translated appropriately, is poorly understood. Our research has capitalized on the Drosophila egg, which relies heavily on maternal transcripts, to investigate mechanisms of mRNA localization and its coupling to translational control. Our early studies focusing on nanos mRNA led to the discovery of a diffusion-and-entrapment mechanism used by numerous transcripts for localization to the specialized germ plasm at the posterior of the oocyte. Produced by the ovarian nurse cells and then transferred to the oocyte, these transcripts are co- packaged at the posterior end into ribonucleoprotein complexes (RNPs) called germ granules. Later during embryogenesis, germ granule mRNAs are segregated as a cohort to the primordial germ cells, where they are required for germline development. Despite their shared dependence on germ granule localization tor translational activation, different transcripts have distinct temporal demands. Our recent studies have led to a stepwise model for germ granule assembly that provides a framework for understanding the composition, structure, and translational properties of RNPs and their functions. Determining the specific roles of shared and RNA-specific proteins in controlling RNP assembly and translation will, in turn, be fundamental to a deeper understanding of mRNA localization as a mechanism for generating protein – and consequently cellular – asymmetries. To elucidate how localized assembly and function of complex RNA granules is controlled, we will take advantage of quantitative high resolution imaging, in vivo fluorescent RNA labeling, and new biochemical strategies to identify cis-acting regulatory elements and interacting proteins that mediate both individualistic and coordinate RNA behaviors. Ribosome footprinting, a genome-level approach for monitoring translation, will be employed to investigate mechanisms that impose translational arrest on unlocalized transcripts. Finally, we will use high resolution imaging of protein synthesis in vivo to decipher the relationship between germ granule association and translational activity.

项目摘要 我们的长期研究目标是了解控制基因活性的转录后机制 早期动物发展。我们专注于细胞内mRNA定位和翻译控制 在确定主要提供的转录本的蛋白质产生中的关键作用。因为这些 控制几乎所有动物的初始发展程序的成绩单都被预载在鸡蛋中， 它们编码的蛋白质的空间和临时表达必须在转录后施加。在动物中 潜水员和青蛙一样，mRNA定位和翻译的局部控制产生不对称蛋白 轴形成，图案和种系开发所需的分布。通常许多不同的成绩单 必须同时定位到各种亚细胞位置。另外，翻译的控制必须是 叠加以抑制非定位的转录本并激活正确局部的转录本。多么特异性 在这些过程中会议，以便每个成绩单针对其正确的目的地并翻译 适当地理解。我们的研究已经大写了果蝇鸡蛋，该蛋 关于母体成绩单，研究mRNA定位的机制及其与翻译的耦合 控制。我们重点关注纳米mRNA的早期研究导致发现了扩散和进程 许多转录本用于定位到专门的种系的机制 卵母细胞。由卵巢护士细胞产生，然后转移到卵母细胞中，这些转录本是共同的 在后端包装到称为胚芽颗粒的核糖核蛋白复合物（RNP）。稍后 胚胎发生，生殖颗粒mRNA被隔离为原始生殖细胞的队列 种系开发所必需的。尽管它们共同依赖细菌颗粒定位 翻译激活，不同的成绩单有不同的临时需求。我们最近的研究导致了 细菌颗粒组件的逐步模型，该模型提供了理解组成的框架 RNP及其功能的结构和翻译属性。确定共享和 控制RNP组装和翻译中的RNA特异性蛋白反过来将是更深的 理解mRNA定位是产生蛋白质的机制（因此是细胞） 不对称。为了阐明如何控制复杂RNA颗粒的局部组装和功能，我们将 利用定量高分辨率成像，体内荧光RNA标记和新的生化 识别顺式作用调节元件和相互作用的蛋白质的策略 和协调RNA行为。核糖体足迹是一种监测翻译的基因组级别方法，将 雇员调查对未含计量转录本施加翻译停滞的机制。最后，我们 将使用体内蛋白质合成的高分辨率成像来解密胚芽颗粒之间的关系 关联和翻译活动。